The present invention relates generally to apparatus for communicating between a host computer and peripheral devices, and more particularly, to a system having a plurality of federated computational input/output circuit card assemblies and a daisy chainable bus that provides communication between a host computer and peripheral devices, and which may advantageously be employed for use with training and simulation systems, and the like.
The assignee of the present invention designs and manufactures training systems, such as flight simulators for military aircraft, such as the F-16, F-18 and F-22 aircraft. Older conventional training systems employed a multiplicity of card types with point to point wiring, mass terminated cables and centrally located housing of devices in the human interface to the system. Older conventional training systems also sampled information using a time sequential framing methodology which propagated data on a subsequent frame from the sample frame. Most training systems use input and output (I/O) devices such as joysticks, switches, potentiometers, electromechanical gauges, LED and LCD displays, CRT displays, and panel lights to provide the human interface to a host computer that implements the simulation. Newer training systems have fewer analog type devices with more integrated digital devices and circuitry for many of the input and output devices, excluding display panel lights, which were higher current devices compared with digital devices.
In the past, communication between the host computer and the peripheral input and output devices was accomplished in a dedicated manner by communications circuitry that was incorporated on a motherboard. However, this dedicated communications circuitry was not compatible with multiple communication protocols that would best match the system's requirements.
Furthermore, in conventional systems, dedicated racks of I/O interface cards were coupled to a dedicated backplane and were typically located as much as 10-12 feet away from the input and output devices to which they were interfaced. A great deal of wiring was required to implement the I/O scheme, and particularly involved a great deal of labor and associated costs. Typically, the card racks were coupled to mass terminated wiring blocks and from the wiring blocks to the individual input and output devices, which was a potential source of problems due to the large number of added terminations. Furthermore, the fact that the I/O cards were located a great distance from the input and output devices required huge wiring looms to be run and the long wiring runs caused unwanted electrical noise problems. In addition prior methodology has produced systems that provide "stale" data to the host computer inherent in the sampling methodology.
It would therefore be an advantage to have apparatus for communicating between a host computer and peripheral input and output devices that provides flexibility in communicating with the input and output devices. It would also be an advantage to have apparatus that eliminates excess wiring and permits location of I/O interface cards in closer proximity to the device that to which the card interfaces. Additionally providing the "freshest" data to a host computer would reduce simulator latency and "simulation misses" due to using data that is out of date.
Accordingly, it is an objective of the present invention to provide for a input/output circuit card assembly that is coupled between a host computer and peripheral devices by way of a daisy-chainable flexible bus constructed in accordance with Firewire (IEEE-1394), RS-232, RS-485, RS-422, or similar specifications that provides communication between the host computer and peripheral devices using a plurality of communication protocols. It is also an objective of the present invention to provide a system that provides the most recent data sampling possible.